The ferrocene-bonding NH2-UIO-66 as an ion sieve to intercept polysulfides and screen Li+ for upgrading performance of lithium-sulfur batteries

Intercepting polysulfides and screening Li+ is one of the most effective methods to achieve high-performance lithium-sulfur (Li-S) batteries. This study focuses on the covalent anchoring of ferrocene into NH2-UIO-66 for the modification of polypropylene (PP) separator. The introduction of ferrocene enables the reduction of the pore size of NH2-UIO-66 from 5.1 Å to 3.9 Å, thereby blocking polysulfides anions and penetrating lithium cations at the molecular level, resulting in significant inhibition in the shuttle effect of polysulfides. The cell with this functional separator exhibits a high initial specific capacity of 1490 mA h g−1 with a capacity decay of 0.018 % after 1000 cycles at 2C. This work provides an effective method of separator modification for high-performance energy storage systems.